+
+ p = getenv("TZ");
+ if( p ) {
+ for( int i=0; ntsc_zones[i]; ++i ) {
+ if( !strcmp(ntsc_zones[i], p) )
+ return "NTSC";
+ }
+ }
+
+//__timezone: Seconds west of UTC. 240sec/deg
+ double tz_deg = -__timezone / 240.;
+// from Honolulu = -10, to New York = -5, 15deg/hr lat -150..-75
+ return tz_deg >= -10*15 && tz_deg <= -5*15 ? "NTSC" : "PAL";